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This review article addresses the role of lung ultrasound in patients with coronavirus disease 2019 (COVID-19) for diagnosis and disease management. As a simple imaging procedure, lung ultrasound contributes to the early identification of patients with clinical conditions suggestive of COVID-19, supports decisions about hospital admission and informs therapeutic strategy. It can be performed in various clinical settings (primary care facilities, emergency departments, hospital wards, intensive care units), but also in outpatient settings using portable devices.The article describes typical lung ultrasound findings for COVID-19 pneumonia (interstitial pattern, pleural abnormalities and consolidations), as one component of COVID-19 diagnostic workup that otherwise includes clinical and laboratory evaluation. Advantages and limitations of lung ultrasound use in COVID-19 are described, along with equipment requirements and training needs. To infer on the use of lung ultrasound in different regions, a literature search was performed using key words “COVID-19”, “lung ultrasound” and “imaging”.Lung ultrasound is a noninvasive, rapid and reproducible procedure; can be performed at the point of care; requires simple sterilisation; and involves non-ionising radiation, allowing repeated exams on the same patient, with special benefit in children and pregnant women. However, physical proximity between the patient and the ultrasound operator is a limitation in the current pandemic context, emphasising the need to implement specific infection prevention and control measures.Availability of qualified staff adequately trained to perform lung ultrasound remains a major barrier to lung ultrasound utilisation. Training, advocacy and awareness rising can help build up capacities of local providers to facilitate lung ultrasound use for COVID-19 management, in particular in low- and middle-income countries.

To assess information reflecting radiation dose and define diagnostic reference levels (DRL) on a European basis for four interventional radiology (IR) procedures considering clinical indication, anatomical region, and procedure. A prospective European study was performed to provide data on the IR procedures percutaneous recanalization of iliac arteries, percutaneous recanalization of femoropopliteal arteries, transarterial chemoembolization of hepatocellular carcinoma, and percutaneous transhepatic biliary drainage. Hospitals were asked to complete a questionnaire giving information on procedure, equipment, and protocol. Patient size and weight, experience of the operator graded in number of procedures performed, and complexity level of each procedure were reported. Sixteen hospitals from 13 countries could be surveyed. The percentiles of the kerma-area product, fluoroscopy time, cumulative air kerma at the interventional reference point, and number of images were determined. The impact of equipment, year of installation, and complexity level of the procedure on dose were analyzed. DRLs based on clinical indication were defined. Dose values varied considerably within hospitals, between them, and within each subgroup of complexity level. The use of state-of-the-art equipment reduced dose significantly by 52%. Although dose also varied within each subgroup of complexity level, for transarterial chemoembolization of hepatocellular carcinoma and percutaneous transhepatic biliary drainage, dose significantly correlated with complexity. This was the first study reporting exposure practice and defining DRLs based on clinical indication for four IR procedures on a European basis. These DRLs can serve as a baseline for comparison with local practice, the study as a guideline for future surveys. • The use of state-of-the-art angiographic equipment reduces dose significantly. • A significant correlation between radiation dose and complexity level is found. • Dose values vary considerably, both within and between individual hospitals, and within each complexity level of interventional radiology procedure.

Abstract In recent years, the issue of cumulative effective dose received from recurrent computed tomography examinations has become a subject of increasing concern internationally. Evidence, predominantly from the USA, has shown that a significant number of patients receive a cumulative effective dose of 100 mSv or greater. To obtain a European perspective, EuroSafe Imaging carried out a survey to collect European data on cumulative radiation exposure of patients from recurrent computed tomography examinations. The survey found that a relatively low percentage of patients (0.5%) received a cumulative effective dose equal to or higher than 100 mSv from computed tomography, most of them having an oncological disease. However, there is considerable variation between institutions as these values ranged from 0 to 2.72%, highlighting that local practice or, depending on the institution and its medical focus, local patient conditions are likely to be a significant factor in the levels of cumulative effective dose received, rather than this simply being a global phenomenon. This paper also provides some practical actions to support the management of cumulative effective dose and to refine or improve practice where recurrent examinations are required. These actions are focused around increasing awareness of referring physicians through encouraging local dialogue, actions focused on optimisation where a team approach is critical, better use of modern equipment and the use of Dose Management and Clinical Decision Support Systems together with focused clinical audits. The proper use of cumulative effective dose should be part of training programmes for referrers and practitioners, including what information to give to patients. Patient summary Radiation is used to the benefit of patients in diagnostic procedures such as CT examinations, and in therapeutic procedures like the external radiation treatment for cancer. However, radiation is also known to increase the risk of cancer. To oversee this risk, the cumulative effective dose (CED) received by a patient from imaging procedures over his or her life is important. In this paper, the authors, on behalf of EuroSafe Imaging, report on a survey carried out in Europe that aims to estimate the proportion of patients that undergo CT examinations and are exposed to a CED of more than 100 mSv. At the same time, the survey enquires about and underlines radiologists’ measures and radiology departments’ strategies to limit such exposure. Over the period of 2015–2018, respondents reported that 0.5% (0–2.72%) of patients were exposed to a CED of ≥ 100 mSv from imaging procedures. The background radiation dose in Europe depends on the location, but it is around 2.5 mSv per year. It is obvious that patients with cancer, chronic diseases and trauma run the highest risk of having a high CED. However, even if the number of patients exposed to ≥ 100 mSv is relatively low, it is important to lower this number even further. Measures could consist in using procedures that do not necessitate radiation, using very low dose procedures, being very critical in requiring imaging procedures and increasing awareness about the issue. Key Points • A relatively low percentage of patients (0.5%) received a cumulative effective dose from CT computed tomography equal to or greater than 100 mSv, in Europe, most of them having an oncological disease. • There is a wide range in the number of patients who receive cumulative effective dose equal to or greater than 100 mSv (0–2.72%) and optimisation should be improved. • Increasing the awareness of referring physicians through encouraging local dialogue, concrete actions focused on optimisation and development of dose management systems is suggested.

The objective of this study was to investigate the feasibility of defining diagnostic reference levels (DRLs) on a European basis for specific clinical indications (CIs), within the context of the European Clinical DRLs (EUCLID) European Commission project. A prospective, multicenter, industry-independent European study was performed to provide data on 10 CIs (stroke, chronic sinusitis, cervical spine trauma, pulmonary embolism, coronary calcium scoring, coronary angiography, lung cancer, hepatocellular carcinoma, colic/abdominal pain, and appendicitis) via an online survey that included information on patient clinical, technical, and dosimetric parameters. Data from at least 20 patients per CI were requested from each hospital. To establish DRLs, a methodology in line with the International Commission on Radiological Protection (ICRP) Report 135 good practice recommendations was followed. Data were collected from 19 hospitals in 14 European countries on 4299 adult patients and 10 CIs to determine DRLs. DRLs differ considerably between sites for the same CI. Differences were attributed mainly to technical protocol and variable number of phases/scan lengths. Stroke and hepatocellular carcinoma were the CIs with the highest DRLs. Coronary calcium scoring had the lowest DRL value. Comparison with published literature was limited, as there was scarce information on DRLs based on CI. This is the first study reporting on feasibility of establishing CT DRLs based on CI using European data. Resulting values will serve as a baseline for comparison with local radiological practice, national authorities when DRLs are set/updated, or as a guideline for local DRL establishment. • First study reporting on the feasibility of establishing CT diagnostic reference levels based on clinical indication using data collected across Europe. • Only one-fourth of the hospitals had CT machines less than 5 years old. • Large dose variations were observed among hospitals and CT protocols were quite different between hospitals.

US physicians in multiple specialties who order or conduct radiological procedures lack formal radiation science education and thus sometimes order procedures of limited benefit or fail to order what is necessary. To this end, a multidisciplinary expert group proposed an introductory broad-based radiation science educational program for U.S. medical schools. Suggested preclinical elements of the curriculum include foundational education on ionizing and nonionizing radiation (eg, definitions, dose metrics, and risk measures) and short- and long-term radiation-related health effects as well as introduction to radiology, radiation therapy, and radiation protection concepts. Recommended clinical elements of the curriculum would impart knowledge and practical experience in radiology, fluoroscopically guided procedures, nuclear medicine, radiation oncology, and identification of patient subgroups requiring special considerations when selecting specific ionizing or nonionizing diagnostic or therapeutic radiation procedures. Critical components of the clinical program would also include educational material and direct experience with patient-centered communication on benefits of, risks of, and shared decision making about ionizing and nonionizing radiation procedures and on health effects and safety requirements for environmental and occupational exposure to ionizing and nonionizing radiation. Overarching is the introduction to evidence-based guidelines for procedures that maximize clinical benefit while limiting unnecessary risk. The content would be further developed, directed, and integrated within the curriculum by local faculties and would address multiple standard elements of the Liaison Committee on Medical Education and Core Entrustable Professional Activities for Entering Residency of the Association of American Medical Colleges.

Objectives This survey conducted by the International Society of Radiology and supported by the European Society of Radiology aimed to collect information regarding radiology departments’ current practices in the management of patients with COVID-19. Methods Responses from 50 radiology departments involved in the management of COVID-19 patients representing 33 countries across all continents were analyzed. The analysis revealed important variations in imaging practices related to COVID-19 across the world for different disease severity and various clinical scenarios. Results Imaging is usually not performed in asymptomatic patients (69% of institutions do not image) but is used at the end of confinement (in 60% of institutions). In the majority of institutions, chest imaging is used in suspected or confirmed patients with COVID-19 (89% and 94%). All imaging departments involved in this survey reported the use of imaging in COVID-19 patients showing severe symptoms or who were critically ill. However, there is a wide variation in imaging modality type used for each clinical scenario. The use of imaging is applied in line with existing guidelines and recommendations in 98% of institutions with structured reporting recorded in 58% of institutions. The vast majority of institutions reported a significant impact of the COVID-19 pandemic on the imaging department’s routine activity (83%). Conclusion We believe that the results of this survey will help to understand current heterogeneities in radiology practice and to identify needs and gaps in the organization and function of radiology departments worldwide in relation to the COVID-19 pandemic. The results of this survey may inform the development of an overall strategy for radiology department organization and imaging protocols in pandemic conditions. Key Points • The results of this survey, which included responses from 50 radiology departments representing 33 countries, showed important variations in imaging practices related to COVID-19 across the world. • While imaging is usually not performed in asymptomatic patients (69% of institutions), it is used in suspected or confirmed patients with COVID-19, in COVID-19 patients showing severe symptoms or who were critically ill, and at the end of confinement (89%, 94%, 100%, 100%, 60% of institutions, respectively). However, there is a wide variation in imaging modality type used for each clinical scenario. • In 98% of institutions, the use of imaging is applied in line with existing guidelines and recommendations, with structured reporting recorded in 58% of institutions. COVID-19 pandemic made a significant impact on the imaging department’s routine activity in 83% of institutions. Electronic supplementary material The online version of this article (10.1007/s00330-020-07252-3) contains supplementary material, which is available to authorized users.

Abstract The European Directive 2013/59/Euratom requires member states of the European Union to ensure justification and optimisation of radiological procedures and store information on patient exposure for analysis and quality assurance. The EuroSafe Imaging campaign of the European Society of Radiology created a working group (WG) on “Dose Management” with the aim to provide European recommendations on the implementation of dose management systems (DMS) in clinical practice. The WG follows Action 4: “Promote dose management systems to establish local, national, and European diagnostic reference levels (DRL)” of the EuroSafe Imaging Call for Action 2018. DMS are designed for medical practitioners, radiographers, medical physics experts (MPE) and other health professionals involved in imaging to support their tasks and duties of radiation protection in accordance with local and national requirements. The WG analysed requirements and critical points when installing a DMS and classified the individual functions at different performance levels. Key Points • DMS are very helpful software tools for monitoring patient exposure, optimisation, compliance with DRLs and quality assurance. • DMS can help to fulfil dosimetric aspects of the European Directive 2013/59/Euratom. • The EuroSafe WG analyses DMS requirements and gives recommendations for users.

The terms "notifications" and "alerts" for medical exposures are used by several national and international organisations. Recommendations for CT scanners have been published by the American Association of Physicists in Medicine. Some interventional radiology societies as well as national authorities have also published dose notifications for fluoroscopy-guided interventional procedures. Notifications and alerts may also be useful for optimisation and to avoid unintended and accidental exposures. The main interest in using these values for high-dose procedures (CT and interventional) is to optimise imaging procedures, reducing the probability of stochastic effects and avoiding tissue reactions. Alerts in X-ray systems may be considered before procedures (as in CT), during procedures (in some interventional radiology systems), and after procedures, when the patient radiation dose results are known and processed. This review summarises the different uses of notifications and alerts to help in optimisation for CT and for fluoroscopy-guided interventional procedures as well as in the analysis of unintended and accidental medical exposures. The paper also includes cautions in setting the alert values and discusses the benefits of using patient dose management systems for the alerts, their registry and follow-up, and the differences between notifications, alerts, and trigger levels for individual procedures and the terms used for the collective approach, such as diagnostic reference levels. KEY POINTS: • Notifications and alerts on patient dose values for computed tomography (CT) and fluoroscopy-guided interventional procedures (FGIP) allow to improve radiation safety and contribute to the avoidance of radiation injuries and unintended and accidental exposures. • Alerts may be established before the imaging procedures (as in CT) or during and after the procedures as for FGIP. • Dose management systems should include notifications and alerts and their registry for the hospital quality programmes.

Imaging has become key in the care pathway of communicable and non-communicable diseases. Yet, there are major shortages of imaging equipment and workforce in low- and middle-income countries (LMICs). The International Society of Radiology outlines a plan to upscale the role of imaging in the global health agenda and proposes a holistic approach for LMICs. A generic model for organising imaging services in LMICs via regional Centres of Reference is presented. The need to better exploit IT and the potential of artificial intelligence for imaging, also in the LMIC setting, is highlighted. To implement the proposed plan, involvement of professional and international organisations is considered crucial. The establishment of an International Commission on Medical Imaging under the umbrella of international organisations is suggested and collaboration with other diagnostic disciplines is encouraged to raise awareness of the importance to upscale diagnostics at large and to foster its integration into the care pathway globally.

Value-based radiology (VBR) is rapidly gaining ground as a means of considering the input of radiology practice into individual and societal healthcare, and represents a welcome move away from older metrics focused on counting studies performed, without consideration of whether these studies contributed positively to patient management or to society as a whole. Intrinsic to the process of considering whether radiology activity confers value is recognising the breadth of involvement of radiology in healthcare delivery; previous ESR and multi-society publications have explored this, and have sought to highlight the many ways in which our specialty contributes to patient welfare. This paper is intended to highlight some current ESR activities which already contribute substantially to value creation and delivery, and to outline a selection of practical steps which could be taken by the ESR in the future to enhance value.Patient summaryValue-based radiology (VBR) is a conceptual means of looking at the benefits conferred on patients and on society as a whole by provision of radiology services, as opposed to older means of counting numbers of radiology studies performed, without consideration of whether or not those studies contributed overall value. VBR will become increasingly important in the future as a means of determining resources. The ESR has been a leader in advancing VBR concepts and educating radiologists about this novel way of looking at what we do. This paper is designed to highlight current ESR activities which contribute value to healthcare, and to consider other ways in which the ESR could potentially support value enhancement in the future.

Aims and objectives: This study aimed to analyse the key factors that influence the overimaging using X-ray such as self-referral, defensive medicine and duplicate imaging studies and to emphasize the ethical problem that derives from it. Materials and methods: In this study, we focused on the more frequent sources of overdiagnosis such as the total-body CT, proposed in the form of screening in both public and private sector, the choice of the most sensitive test for each pathology such as pulmonary embolism, ultrasound investigations mostly of the thyroid and of the prostate and MR examinations, especially of the musculoskeletal system. Results: The direct follow of overdiagnosis and overimaging is the increase in the risk of contrast media infusion, radiant damage, and costs in the worldwide healthcare system. The theme of the costs of overdiagnosis is strongly related to inappropriate or poorly appropriate imaging examination. Conclusions: We underline the ethical imperatives of trust and right conduct, because the major ethical problems in radiology emerge in the justification of medical exposures of patients in the practice. A close cooperation and collaboration across all the physicians responsible for patient care in requiring imaging examination is also important, balancing possible ionizing radiation disadvantages and patient benefits in terms of care.

The diagnosis and treatment of patients with cancer requires access to imaging to ensure accurate management decisions and optimal outcomes. Our global assessment of imaging and nuclear medicine resources identified substantial shortages in equipment and workforce, particularly in low-income and middle-income countries (LMICs). A microsimulation model of 11 cancers showed that the scale-up of imaging would avert 3·2% (2·46 million) of all 76·0 million deaths caused by the modelled cancers worldwide between 2020 and 2030, saving 54·92 million life-years. A comprehensive scale-up of imaging, treatment, and care quality would avert 9·55 million (12·5%) of all cancer deaths caused by the modelled cancers worldwide, saving 232·30 million life-years. Scale-up of imaging would cost US$6·84 billion in 2020-30 but yield lifetime productivity gains of $1·23 trillion worldwide, a net return of $179·19 per $1 invested. Combining the scale-up of imaging, treatment, and quality of care would provide a net benefit of $2·66 trillion and a net return of $12·43 per $1 invested. With the use of a conservative approach regarding human capital, the scale-up of imaging alone would provide a net benefit of $209·46 billion and net return of $31·61 per $1 invested. With comprehensive scale-up, the worldwide net benefit using the human capital approach is $340·42 billion and the return per dollar invested is $2·46. These improved health and economic outcomes hold true across all geographical regions. We propose actions and investments that would enhance access to imaging equipment, workforce capacity, digital technology, radiopharmaceuticals, and research and training programmes in LMICs, to produce massive health and economic benefits and reduce the burden of cancer globally.

The World Health Organization (WHO) undertook the development of a rapid guide on the use of chest imaging in the diagnosis and management of COVID-19. The rapid guide was developed over two months using standard WHO processes, except for the use of 'rapid reviews' and online meetings of the panel. The evidence review was supplemented by a survey of stakeholders regarding their views on the acceptability, feasibility, impact on equity and resource use of the relevant chest imaging modalities (chest radiography, chest CT and lung ultrasound). The guideline development group had broad expertise and country representation. The rapid guide includes three diagnosis recommendations and four management recommendations. The recommendations cover patients with suspected or confirmed COVID-19 with different levels of disease severity, throughout the care pathway from outpatient facility or hospital entry, to home discharge. All recommendations are conditional and are based on low certainty evidence (n=2), very low certainty evidence (n=2), or expert opinion (n=3). The remarks accompanying the recommendations suggest which patients are likely to benefit from chest imaging and what factors should be considered when choosing the specific imaging modality. The guidance also offers considerations about implementation, monitoring and evaluation, and identifies research needs.

Clinical audit “according to national procedures” is a legal requirement as defined within the recently implemented European Council Basic Safety Standards Directive (BSSD), 2013/59/Euratom. A survey was undertaken in 2019 to assess the current status of clinical audit in European radiology departments and for feedback on the recently published “ESR Guide to Clinical Audit in Radiology” and the “ESR Clinical Audit Tool (Esperanto)”. The survey was distributed within the European Society of Radiology (ESR) EuroSafe Imaging Star network and also to European national radiological societies which are institutional members of the ESR.A total of 47/116 (41%) EuroSafe Imaging Star departments responded, and responses were received from 43 radiology departments from 16/48 national radiological societies.Survey findings demonstrated a low awareness of recent key ESR audit-related publications (Esperanto), a lack of clinical audit infrastructure for BSSD compliance and by inference a poorly developed local/national communication and audit infrastructure in many cases.Key stakeholders, including the ESR and the European national radiological societies, will need to continue to work with other bodies to further promote, integrate and to encourage resourcing of clinical audit at all levels, facilitating BSSD compliance and improving patient care.

Purpose The purpose of this study was first to evaluate the imaging-related cumulative post-transplantation radiation dose in cystic fibrosis (CF) lung transplantation (LT) recipients and second, to identify the occurrence and type of malignancies observed after LT. Materials and methods A total of 52 patients with CF who underwent LT at our institution between January 2001 and December 2006 with at least 3 years of survival were retrospectively included. There were 27 men and 25 women with a mean age of 24.4 ± 9.2 (SD) years (range: 7.6–52.9 years) at the time of LT. Calculation of cumulative effective and organ doses after LT were based on dosimetry information and acquisition parameters of each examination. Cumulative radiation doses were calculated until June 2016, but stopped at the time of de novomalignancy diagnosis, for patients developing the condition. Results Patients received a mean cumulative effective dose of 110.0 ± 51.6 (SD) mSv (range: 13–261.3 mSv) over a mean follow-up of 8.1 ± 3.6 (SD) years (range: 0.5–13.5 years), with more than 100mSv in 5 years in 19/52 patients (37%). Chest CT accounted for 73% of the cumulative effective dose. Mean doses to the lung, breast and thyroid were 152.8 ± 61.1 (SD) mGy (range: 21.2–331.6 mGy), 106.5 ± 43.2 (SD) mGy (range: 11.9–221.4 mGy) and 72.7 ± 31.8 (SD) mGy (range: 9.5–165.0 mGy), respectively. Nine out of 52 patients (17%) developed a total of 10 de novo malignancies, all but one attributable to immunosuppression after a mean post-transplantation follow-up period of 11.1 ± 3.5 (SD) years (range: 3.7–16.3 years). Six-month cumulative effective dose was not greater in patients with de novomalignancies than in those without de novomalignancies (28.9 ± 14.5 (SD) mGy (range: 13.0–53.4) vs 25.6 ± 15.3 (range: 5.0–69.7), respectively, P > 0.05). Conclusion The cumulative effective dose exceeded 100 mSv in 5 years in 37% of LT recipients, the reason why continuous efforts should be made to optimize chest CT acquisitions accounting for 73% of the radiation dose.

The ACR, the European Society of Radiology, and the International Society of Radiology held the first joint Global Summit on Radiological Quality and Safety in May 2013. The program was divided into 3 day-long themes: appropriateness of imaging, radiation protection/infrastructure, and quality and safety. Participants came from global organizations, including the International Atomic Energy Agency, the World Health Organization, and other institutions; industry and patient advocacy groups with an interest in imaging were also represented. The goal was to exchange ideas and solutions and share concerns to arrive at a better and more uniform approach to quality and safety. Participants were asked to use the information presented to develop strategies and tactics to harmonize and promote best practices worldwide. These strategies were summarized at the conclusion of the meeting.

To independently evaluate unenhanced, contrast-enhanced perfusion and angiographic MR sequences for pulmonary embolism (PE) diagnosis.Prospective investigation, including 274 patients who underwent perfusion, unenhanced 2D steady-state-free-precession (SSFP) and contrast-enhanced 3D angiographic MR sequences on a 1.5-T unit, in addition to CTA (CT angiography). Two independent readers evaluated each sequence independently in random order. Sensitivity, specificity, predictive values and inter-reader agreement were calculated for each sequence, excluding sequences judged inconclusive. Sensitivity was also calculated according to PE location.Contrast-enhanced angiographic sequences showed the highest sensitivity (82.9 and 89.7 %, reader 1 and reader 2, respectively), specificity (98.5 and 100 %) and agreement (kappa value 0.77). Unenhanced angiographic sequences, although less sensitive overall (68.7 and 76.4 %), were sensitive for the detection of proximal PE (92.7 and 100 %) and showed high specificity (96.1 and 99.1 %) and good agreement (kappa value 0.62). Perfusion sequences showed lower sensitivity (75.0 and 79.3 %), specificity (84.8 and 89.7 %) and agreement (kappa value 0.51), and a negative predictive value of 84.8 % at best.Compared with contrast-enhanced angiographic sequences, unenhanced sequences demonstrate lower sensitivity, except for proximal PE, but high specificity and agreement. The negative predictive value of perfusion sequences was insufficient to safely rule out PE.• Unenhanced angiographic MR sequences are very specific and can identify proximal PE. • Contrast-enhanced MR angiographic sequences show high sensitivity for PE diagnosis. • A normal MR perfusion result does not exclude PE. • Inter-reader agreement is better for angiographic than perfusion MR sequences.

Resume Chez l’insuffisant renal, les produits de contraste iodes peuvent etre responsables d’une insuffisance renale aigue et les produits gadolines peuvent induire une fibrose systemique nephrogenique. L’injection doit donc etre un acte medical reflechi et l’evaluation de la fonction renale prend une grande importance, bien que son estimation par des formules a partir de la creatininemie soit soumise a des fluctuations. Pour les produits iodes, la nephropathie induite (CIN) sera prevenue par une hydratation prealable, idealement intraveineuse, quand la clairance de la creatinine est inferieure a 60 ml/min. Quand le produit de contraste est injecte par voie intraveineuse, le risque est moindre que par voie intra-arterielle et le seuil pour l’hydratation peut etre abaisse a 45 ml/min. Pour les produits gadolines, le groupe a risque de fibrose systemique est le patient en insuffisance renale terminale ou en dialyse. Dans ces cas, l’injection d’un chelate de gadolinium n’est possible qu’apres avoir mesure le rapport benefice–risque, choisi un lineaire substitue ou un macrocycle et limite la dose a 0,1 mmol Gd/kg. Les recommandations europeennes et americaines des agences de sante se sont rapprochees tres recemment. Objectifs pedagogiques : connaitre les facteurs de risque de nephropathie induite par les produits iodes ; connaitre les modalites d’hydration d’un patient a risque de nephropathie induite par les produits iodes ; connaitre les criteres diagnostiques de la fibrose systemique nephrogenique ; connaitre la classification des produits de contraste gadolines en fonction du risque de FSN ; connaitre les contre-indications des differents groupes de produits de contraste gadolines.

To evaluate the rate of positive, negative, and indeterminate results and the agreement between initial and expert readings for lung scintigraphy and computed tomographic (CT) angiography performed in patients suspected of having pulmonary embolism (PE) during pregnancy.Institutional review board approval was obtained. The authors retrospectively analyzed the images from lung scintigraphy and CT angiography performed in pregnant patients during the past 9 years. Images from 46 CT angiographic examinations performed in 43 patients and 91 of 94 lung scintigraphic examinations were reviewed by experts, whose readings were then compared with the initial reports. For CT angiography, the quality of opacification was graded as good, suboptimal, or poor and intraarterial attenuation was measured.The rates of positive findings (seven of 43 patients [16%] with CT angiography and 10 of 91 patients [11%] with scintigraphy, P = .36), negative findings (28 of 43 patients [65%] with CT angiography and 64 of 91 patients [70%] with scintigraphy, P = .54), and indeterminate findings (eight of 43 patients [19%] with CT angiography and 17 of 91 patients [19%] with scintigraphy, P = .99) were similar for CT angiography and lung scintigraphy. There were four discrepancies between initial and expert readings for CT angiography (κ = 0.84; confidence interval: 0.68, 0.99) and 14 for lung scintigraphy (κ = 0.75; 95% confidence interval: 0.63, 0.87). Opacification was classified as good for only 23 of the 46 CT angiographic examinations (50%). Attenuation values were significantly different among the groups with good, suboptimal, or poor opacification. Alternative diagnoses unsuspected at chest radiography were demonstrated at CT angiography in five of the 43 patients (12%). The mean maternal radiation dose was 0.9 mSv for lung scintigraphy and 7.3 mSv for CT angiography.Lung scintigraphy and CT angiography have comparable performances for PE diagnosis during pregnancy. Interobserver agreement is better for CT angiography, which also enables alternative diagnosis of unsuspected disease but delivers higher maternal radiation dose.

Clinical imaging guidelines are the most practical format to provide referring doctors with guidance on appropriate imaging based on clinical indications. But, while they have been available for decades, guidelines are hardly used in clinical practice, and study after study shows that medical imaging is utilised inappropriately to a significant degree. The best way to increase the use of guidelines in clinical practice without significantly disrupting or delaying the referral workflow are clinical decision support (CDS) systems. Implementing guidelines through integrated CDS has several benefits compared to text-based guidelines or stand-alone, static applications. The guidelines can be updated continuously, and updates can be deployed to users in very short intervals. Updating comprehensive guidelines is an extensive process, and for entire guideline sets, updated editions are often only released every five years or less. Integrated CDS provides users with guideline-based recommendations within their native workflow, so they do not have to use a different system, or even open a separate browser window. Anonymous patient parameters like patient age and sex are automatically sent to the order entry system so that users need only select the reason for exam. Implementation not only depends on technical aspects and a streamlined user experience, there are other factors to consider. In Europe, the availability of referral guidelines is a requirement for EU member states according to the Basic Safety Standards Directive (2013/59/Euratom). This directive is a welcome driver to increase the adoption and use of referral guidelines in clinical practice. While this applies across the EU, the healthcare systems, utilisation of medical imaging, and incentives at work are very different, requiring a tailored strategy for promoting the implementation of guidelines in each country. This is why the ESR’s EuroSafe Imaging campaign has established a working group to promote the implementation of guidelines through clinical decision support this year. Working with national radiology societies, radiation protection campaigns, national authorities and other stakeholders, the group’s purpose is to identify strategies for maximising the adoption of evidence-based guidelines, and their application in clinical practice.

Summary. Background: The diagnostic value of indirect computed tomographic venography (CTV), following thoracic computed tomographic angiography (CTA), has not been specifically evaluated in postpartum patients with suspected pulmonary embolism. Objectives: To assess the diagnostic value of CTV in postpartum venous thromboembolism. Methods: We reviewed all CTA and CTV procedures performed during the last 7 years in our institution for suspected pulmonary embolism during the postpartum period. We focused on the quality of CTA, the rates of positive CTA and isolated positive CTV findings, and alternative diagnoses provided by CTV. Results: Fifty-five CTA and 33 CTV procedures were performed for suspected pulmonary embolism in 47 patients referred between 24 h and 2 months after Cesarean (34 patients) or vaginal (13 patients) delivery. Of the 33 patients who had both CTA and CTV, seven had positive CTA findings and four had isolated positive CTV findings. Thus, the absolute increase in the venous thromboembolism detection rate following CTV was 12.1% [95% confidence interval (CI) 4.0–29.1]. Subcapsular hematoma of the liver or spleen was found on CTV in another two patients without venous thromboembolism. Consequently, CTV had a direct impact on clinical management in six of 33 patients (18%). Conclusion: Our results suggest that postpartum patients with suspected pulmonary embolism have a significant rate of pelvic vein thrombosis and that the use of CTV leads to a 31% relative increase in the detection rate of venous thromboembolism as compared to CTA alone in these patients.

To retrospectively determine sensitivity and specificity of four findings for distinguishing pulmonary infarction from other causes of peripheral pulmonary consolidations on multidetector computed tomographic (CT) images, with other CT and clinical findings as reference.Institutional review board approved the study and waived informed consent. Three independent radiologists blindly analyzed selected multisection CT images of 50 pulmonary infarctions-not showing direct arterial signs of pulmonary embolism-and 100 peripheral consolidations of other origins. Readers analyzed four findings: triangular shape, vessel sign (defined as presence of an enlarged vessel at the apex of consolidation), central lucencies, and air bronchograms. Interobserver agreement; frequency on CT images with and without infarct; and sensitivity, specificity, and positive likelihood ratio (LR) for diagnosis of pulmonary infarction were assessed for each finding.One hundred fifty peripheral consolidations were analyzed in 134 (75 men, 59 women) patients (mean age, 55.9 years+/-17.4 [standard deviation] vs 54.7+/-19.9; P=.71). Interobserver agreement was good for central lucencies and air bronchograms and poor to moderate for the other two findings (kappa0.61). Compared with CT images without infarct, CT images with infarct had a higher frequency of vessel sign (32% [16 of 50] vs 11% [11 of 100], P=.029) and central lucencies (46% [23 of 50] vs 2% [two of 100], P.001) and a lower frequency of air bronchograms (8% [four of 50] vs 40% [40 of 100], P=.003). Frequency of triangular shape was similar in both groups (52% [26 of 50] vs 40% [40 of 100], P=.17). Positive LR was 23.0 for central lucencies, 2.9 for vessel sign, 1.3 for triangular shape, and 0.2 for air bronchograms. Presence of central lucencies had 98% specificity and 46% sensitivity for pulmonary infarction. When the vessel sign and negative air bronchogram were combined with central lucencies, specificity increased to 99% but sensitivity decreased to 14%.Central lucencies in peripheral consolidations are highly suggestive of pulmonary infarction.

Escalating costs and inadequate quality and safety are major concerns of health care at this time. The first, increasing cost of health care worldwide, can be attributed in part to the aging of populations, but it is also due to the successful treatment of acute illnesses and the resultant shift toward the expense of caring for the chronically ill, which now accounts for 75% of the costs (1). But with 2001 health care costs comprising 14% of the gross domestic product in the United States and with an expected increase to 18% by 2012 (2), there is considerable pressure from employers, insurance companies, and the government to limit health care spending to a sustainable amount and to make the system more accountable. Radiology is not immune to these worldwide health care concerns. In 1990, U.S. radiology costs accounted for about 3.5% of the national spending on health care (3). Overall, diagnostic radiology utilization rate increases have been modest in the United States, with a 3.1% compound annual increase for Medicare enrollees in the period 1992–2001 (4). However, utilization of high-cost radiology services increased dramatically in the past decade, as has been demonstrated for Medicare enrollees (4–9), privately insured groups (4,6,8), and within individual institutions (10,11). Data for Medicare enrollees, which are more complete than those for other populations, show a trend of double-digit annual rate increases in utilization of computed tomography (CT), magnetic resonance (MR) imaging, and nuclear imaging in the years 1992–2001 (4). The second major health care concern involves quality and safety. The rate of adverse events in medical care in the United States is 3%–4% (12,13), which may result in $28 billion in unnecessary expense and as many as 44 000–98 000 deaths per year due to provider error (14). In radiology practice, quality includes obtaining the best possible images through quality assurance programs and through the appropriate selection of modality and protocol. Safety issues include avoiding injury due to the effects of magnetic fields on metallic implants, contrast agent reactions, radiation exposure, and ensuring that there is adequate monitoring of patients for adverse events. Rapid technologic advances in radiology have increased the concerns regarding utilization, as well as quality and safety. By the end of the second millennium, computerized workstations have now become commonplace, picture archiving and communications systems (PACS) and radiology information systems (RIS) are widespread, the Internet is almost essential for the transfer of images and other information, and computer-aided detection (CAD) has been developed as a useful tool. Recent innovations in imaging suggest that radiology will be a major catalyst for transforming medicine into an age of information technology and molecular medicine.

Imaging plays a crucial role in oncology to assist in the management of patients and selection of drug regimen. Recent advances in imaging techniques allowing to predict and evaluate response to treatments in oncology will be reviewed. The standard in the evaluation of response to treatment is based on the measurement of lesion size. Functional imaging assesses physiological or molecular processes that may be earlier indicators of early response to treatment. Dynamic imaging of tumor vascularization assesses the biodistribution of a contrast agent within tumoral tissues. Diffusion-weighted MR imaging can differentiate free water from water restricted by tissues, providing an assessment of tumor cellularity. MR spectroscopy assesses the relative quantity of specific chemical components within normal and tumoral tissues. 18 FDG PET imaging provides an assessment of the metabolic activity of tissues. FDG uptake is proportional to cellular proliferation and number of viable cells within a tumor. Results from studies assessing the role of these emerging imaging techniques remain preliminary and the medical community must determine their respective role in the routine evaluation of response to treatment in oncological patients.

PURPOSE: To assess placental perfusion and permeability in mice with magnetic resonance (MR) imaging. MATERIALS AND METHODS: This study was conducted according to French law and National Institutes of Health recommendations for animal care. Twenty-two pregnant BALB/c mice were examined at 1.5 T with a single-section dual-echo fast spoiled gradient-echo sequence. Two injection protocols were used: monophasic injection (double the clinical dose of contrast agent) and biphasic injection (quadruple the clinical dose). Signal intensities (SIs) were measured in the maternal left ventricle, placenta, and fetus (n = 16). At these high gadolinium doses, a T2* effect correction was used. SIs were converted to gadolinium concentrations and were analyzed by using a three-compartment model. Quantitative microcirculation parameters were calculated. Results with the monophasic and biphasic protocols were compared, and final arterial concentrations determined with MR imaging were compared with those determined with atomic emission spectrophotometry by using the unpaired Student t test. RESULTS: Perfusion and permeability parameters for monophasic and biphasic injections were similar: Mean placental blood flow was 180 mL/min/100 g, mean permeability surface coefficient from maternal placental to fetal placental compartment was 10.3 x 10(-4) sec(-1) +/- 6.81 (standard deviation), mean permeability surface coefficient from fetal placental to maternal placental compartment was 4.65 x 10(-4) sec(-1) +/- 4.37, and mean fractional volume of the maternal vascular placental compartment was 36.5% +/- 0.9. Placental (146 vs 105 micromol/L, P < .004) and fetal (33.3 vs 19.1 micromol/L, P < .001) gadolinium concentrations were higher with the biphasic than with the monophasic protocol. Arterial gadolinium concentrations at MR imaging did not differ significantly from those at spectrophotometry for the monophasic (P = .254) or biphasic (P = .776) injection protocol. CONCLUSION: Placental perfusion and permeability can be measured in vivo by using high gadolinium doses and a dual-echo MR imaging sequence.

Imaging in cancer plays a capital role to guide the clinician in his choice of therapies. We will discuss the new techniques available to predict and evaluate treatment response in oncology. The method of reference to evaluate treatment response is based on the measure of lesion size. Functional imaging doesn't evaluate size, but rather a physiological or molecular feature, which is probably modified earlier in response to treatment. Dynamic contrast-enhanced functional imaging of microcirculation follows the biodistribution of a contrast agent and analyses tumour vascularization. Diffusion-weighted Magnetic Resonance Imaging differentiates free and restrained water molecules in tissues, reflecting tumor cellularity. Nuclear Magnetic Resonance spectroscopy is an application of MRI that yields information on the metabolic content of a tissue. It detects relative quantities of various molecules which differ in tumour compared to normal tissue. Positon-emission tomography using (18)FDG is a nuclear medicine technique which gives information on tissue metabolism. Captation of FDG is proportional to the proliferative activity and the number of viable cells in a tumour. Human studies concerning these techniques are still quite preliminary, and the medical community must determine their potential in clinical practice to evaluate treatment response in oncology.

The purpose of our study was to evaluate the reliability of software-calculated doubling times for discerning malignant versus benign nodules.CT lung analysis volumetric software was used to retrospectively calculate the doubling times of 63 solid noncalcified nodules by comparing nodule volumes on baseline and follow-up CT scans obtained a median of 3.7 months apart. A final diagnosis based on validated criteria was available for all 63 nodules. All CT examinations were performed with 1.25-mm-thick slices on a four-detector unit. Taking 500 days as the upper value for malignancies, we evaluated whether the software-calculated doubling times could be used to distinguish malignant from benign solid nodules. We also examined whether the relative volume variation of benign nodules correlated with initial nodule size, interscan interval, or differences in contrast administration or exposure parameters between baseline and follow-up CT.There were 52 benign and 11 malignant nodules. Benign nodules had a median doubling time of 947 days and a mean relative volume variation of -4.4% (range, -50% to 38%). Malignant nodules had a median doubling time of 117 days and a mean relative volume variation of 102% (22-462%). The sensitivity, specificity, and negative and positive predictive values of the volumetric software for diagnosing malignancy were 91% (95% confidence interval [CI], 0.59-1.00), 90% (95% CI, 0.79-0.97), 98% (95% CI, 0.89-1.00), and 67% (95% CI, 0.38-0.88), respectively. No correlation was found between the relative volume variation of benign nodules and their initial size, the interscan interval, or differences in contrast administration or exposure parameters between the two CT examinations.Software-calculated pulmonary nodule doubling times of more than 500 days have a 98% negative predictive value for the diagnosis of solid malignant pulmonary nodules. This method may be useful for diagnosing malignant pulmonary nodules on follow-up CT.

Placental insufficiency, a process due to either poor placental perfusion or permeability, may lead to progressive deterioration in placental function and materno-fetal morbidity. Advances in MR contrast media pharmacokinetic studies of transit through tissues and dynamic MRI allow to characterize organs microcirculation in vivo. Placental function assessment might be achieved using analysis of dynamic contrast enhanced MRI of tracers. A murine model of placental assessment has been constructed. Herein, principles, results and limitations of such techniques are discussed as well as their potential interest and weaknesses in humans.

To evaluate a magnetic resonance (MR) imaging contrast agent for tumor detection based on paramagnetic nonionic vesicles (niosomes) bearing polyethylene glycol (PEG) and glucose conjugates for the targeting of overexpressed glucose receptors.Four gadobenate dimeglumine-loaded niosome preparations including nonconjugated niosomes, niosomes bearing glucose conjugates (N-palmitoyl glucosamine [NPG]), niosomes bearing PEG 4400, and niosomes bearing both PEG and NPG were tested. In vitro cellular uptake was measured at electron paramagnetic resonance (EPR) after incubation with human prostate carcinoma, PC3, cells. In vivo distribution was studied at MR imaging 6, 12, and 24 hours after injection, with assessment of tumor, brain, liver, and muscle signal intensity (SI) in 49 mice bearing PC3 cells. Efficiency of targeted contrast agents was assessed with tumor-to-muscle contrast-to-noise ratio (CNR). Testing for differences was performed with analysis of variance followed by a posteriori Fisher test.In vitro, gadolinium could be detected at EPR only in cell pellets incubated with niosomes bearing glucose conjugates or niosomes bearing both glucose conjugates and PEG (4.9. 10(-15) and 4.5. 10(-15) mol gadolinium per PC3 cell). In vivo, marked predominant tumor enhancement was demonstrated 24 hours after injection of glycosylated PEG niosomes (P.01); no significant differences were observed following injection of nonconjugated niosomes, glycosylated niosomes, or PEG 4400 niosomes. Twenty-four hours after injection, sole presence of NPG or PEG 4400 on the surface of the niosome led to higher tumor-to-muscle CNR than that observed after injection of nonconjugated niosomes (CNR of 3.3 +/- 0.7 [SD], 3.4 +/- 2.2, and 0 +/- 1.9). Combination of NPG and PEG led to even higher tumor-to-muscle CNR (6.3 +/- 2.2).Combination of PEG and glucose conjugates on the surface of niosomes significantly improved tumor targeting of an encapsulated paramagnetic agent assessed with MR imaging in a human carcinoma xenograft model.

Background: Magnetic resonance imaging (MRI) contrast agents contain magnetic molecules such as iron (Fe) or gadolinium (Gd) that are injected in vivo into rats or mice to study their distribution inside the liver. Fluorescent europium (Eu) can be used as a model of Gd to obtain comparable information of this distribution of corresponding contrast agents. In a similar approach, Fe can be attached to Texas Red and used as a model of ferumoxides and be detected by fluorescence. Methods: To combine and compare the advantages of different microscopic imaging modes, characterization studies were carried out by means of a confocal laser scanning microscope (CLSM), a secondary ion mass spectrometric (SIMS) microscope, and an electron energy loss spectrometric (EELS) microscope. In the case of CLSM, the locations of fluorescent signals inside preparations were determined by factor analysis of biomedical image sequences (FAMIS) and selection of image sequences at emission. Results: By CLSM and FAMIS, we distinguished chelated Eu and Texas Red attached to Fe. By SIMS microscopy, we distinguished Eu and Gd of chlorides and chelates and Fe of a ferumoxide. By EELS microscopy, we distinguished Eu and Gd of chlorides. Conclusions: Analysis of compounds inside correlative specimens by means of CLSM, SIMS, and EELS microscopes provided complementary results. Cytometry Part A 51A:97-106, 2003. (C) 2003 Wiley-Liss, Inc.